No, smartwatches cannot directly measure glucose levels. The US Food and Drug Administration (FDA) says to avoid devices that claim to do this, warning of the possible health risks.

Despite an ample supply of smartwatches and smart rings being sold through online marketplaces that claim to directly measure blood glucose, the FDA says it has not reviewed any such device.

“The FDA has not authorised, cleared, or approved any smartwatch or smart ring that is intended to measure or estimate blood glucose values on its own,” the agency said in a safety communication aimed at consumers, patients, and health care providers.

The erroneous claims by manufacturers are especially dangerous to those living with diabetes. Inaccurate blood glucose measurements can lead to incorrect doses of insulin or other medications used to manage the disease. Dangerously high doses of insulin can even lead to death.

The agency was keen to differentiate approved products that use sensors to pierce the skin. Continuous glucose monitors (CGMs) such as Abbott’s Freestyle Libre and DexCom’s G6 are regulated by the FDA and reliably measure blood sugar levels.

Currently, there are no approved devices that non-invasively measure blood glucose levels. Apple is reportedly developing technology that would allow its smartwatches to do this yet it is unclear how the tech giant will interact with the FDA. The company has already had to double back on a pulse oximetry feature following a patent infringement with Masimo. Bloomberg reported that Apple might create a feature that tells users if their glucose levels are heading in the wrong direction as opposed to measuring precise data.

The FDA said it is working to ensure that manufacturers, distributors, and sellers do not illegally market unauthorised smartwatches or smart rings that claim to measure blood glucose levels.

The global market for authorised blood glucose meters was worth $4.7bn in 2023 and is forecast to grow to $6.7bn by 2033, according to a report by GlobalData.